Abstract

The main subject of this seminar is to understand the production of quarkonia in more detail, utilising their production in jets. Previous quarkonia in jets measurements from LHCb and CMS have shown discrepancies between data and current Pythia 8 MC predictions when measuring the normalised cross section vs. z(J/ψ) ≡ pT(J/ψ)/pT(jet) for prompt J/ψ’s. Pythia 8 predicts an isolated peak at z(J/ψ) ≃ 1 in comparison to data which is less isolated. First, new measurements performed by LHCb to try and understand this discrepancy will be discussed, namely normalised cross sections vs. z for different quarkonia (J/ψ, ψ(2S), Υ(1S), Υ(2S), Υ(3S) and X(3872)). Second, to address this discrepancy in Pythia 8 MC, the introduction of quarkonia fragmentation functions into the parton shower framework is discussed, which are calculations based on the effective field theory, non-relativistic QCD (NRQCD).